Heat stress cramps: what to know

Working or exercising in hot weather can cause heavy sweating. Losing water and salts, combined with muscle fatigue, may make the calves, thighs, shoulders, or abdomen tighten painfully. Cramps can start during activity or later while resting. They can occur alongside [Muscle Aches](/symptoms/muscle-aches/) and thirst, but a severe illness may be developing if weakness, dizziness, confusion, or vomiting appears.

Stop the activity and sit or lie in a cool place. Remove unnecessary layers, apply cool damp cloths, and gently stretch the cramped muscle without forcing it. If you are awake and able to swallow, take small sips of water or an oral rehydration drink. [Oral Rehydration Therapy](/treatments/acute-and-urgent-care/oral-rehydration-therapy/) may be discussed when fluid loss is significant. Avoid alcohol and do not return to exertion until the cramp and other symptoms have settled.

Seek urgent care for confusion, fainting, seizure, breathing difficulty, collapse, severe weakness, or inability to drink. Get medical advice if cramps do not improve with cooling and rest, keep recurring, or are accompanied by worsening [Dehydration](/conditions/dehydration/) symptoms. People with kidney, heart, or other long-term conditions should seek personalised fluid advice.

Ask which drinks are appropriate for your health, how to pace activity in hot weather, and whether medicines or another condition could increase fluid loss. Share when the cramps began, the body areas affected, heat exposure, sweating, and any dizziness or vomiting.